Telephone-transmitter.



. PATENTED APR. 18, 19051 nB. P'. GLAUSEN. TELEPHONE TRANSMITTER.

APPLIOATIGN IILEDUG. 19, 1901..

2 SHEETS-SHEET l.

Izvenar @PCM/usen Witnesses.'

' Witnesses:

No. 787,610. PATENTED APR. 18, 1905.

H. P. CLAUSEN.

TELEPHONE TRANSMITTER. AA1=1 1.10AT10N FILED AUG. 19, 1901.

2 SHEETS-SHEET 2.

l WMM.

Aio

UNITED STATES Patented Aprii 1s, i eos.

PATENT. OFFICE.

HENRY P. CLAUSEN, OF CHICAGO, ILLINOIS, ASSIGNOR TO AMERI-v CAN ELECTRIC TELEPHONE COMPANY, A CORPORATION OF-NEW JERSEY.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of" Letters Patent- No. 787,610, dated April 18, 1905.

Application filed August 19, 1901. Serial No. 72.623.

To all, whom it may concern: Be it known that I, HENRY P. CLAUSEN, a citizen of the United States of America, and a resident of Chicago, Cook county, Illinois, have invented a certain new and useful Iinprovement in Telephone Transmitte'` s, of which the following is a specification.

My invention relates to certain improveyments in telephone-transmitters of the type ordinarily known as a microphone.

In a telephone-transmittera thin circular disk of suitable material, preferably of cai'- bon or some metal, called 'the "diaphragm, is held in a suitable case in proximity to a mouthpiece,- so that the articulated soundwaves are concentrated upon the diaphragm which is held at its edges, and thus vibrate the diaphragm. It is necessary to providea conducting material which shall be iniuenced by the vibrations of the diaphragm to Vary the intensity otA an electric current. The material which has usually been employed in the modern types of transmitters for this purpose is granular carbon,` which is held within a suitable receptacle. The electrodes or the members with which the circuit-wires are connected usuallyconsist of-cai'bon disks held apart by the mass of granular carbon interposed between them, one ot' said disks of carbon being connected with the diaphragm. so that the vibrations of the latter are imparted to the former, causing said electrode -to approach toward and recede from the other car- -hon disk or electrode. `.35

By this means thc mass oi granular carbon is varied in its density, and as the electric current passes through the mass of carbon the resistance ot' `the circuit.

I varies in proportion to the variation of density of the mass of carbon granules.

In transmitters generallyY it isdesirable to provide a self-contained piece of apparatus the parts of which are readily and convenientlyadjiisted and which when adjusted remain in secure and permanent relationshipand also to produce a completed piece of apparatus which is small and compact. lt is of further importance to .provide means by which the electrode or carbon disk connected with and moved by the diaphragm shall have a y instrument.

maximum amplitude of vibration, and thereby act to vary the range of density of the mass of carbon granules. l My invention is particularly designed to obtain in atransinitter of this type a maximum range of vibration or movement oi' the diaphragm-electrode in its relation to" the relatively fixed back electrode. To do this, I pro-- v'idea shell formed of twov parts joined and held together, which when assembled provides an annular receptacle'having springt7 or resilient supplemental diaphragm or walls and an intermediate annular body of material which, presenting its cross-section'to the line of stress, is i'niexible. The diaphragm-electrode or disk of carbon is mounted upon one flexible springy wall of the receptacle, and thc back electrode is mounted upon the other iiexible Awall of said receptacle, the mass of granular carbon 'being disposed within said receptacleand between said carbon electrodes. The diaphragm is secured to vone wall of the receptacle, and the center of the other wall of the receptacle is rigidly secured to what is knownas the supporting-bridge, which latter is connected to the casing or rimof 'the Thus the vibrations of the diaphragm are imparted to the spriiigy front wall of the receptacle aiidto the diaphragmelectrode secured thereto; but as the other wall is only securedto the back electrode at its center it has a marginal vibration imparted to it through the annular intermediate ring of the receptacle, which permits a further and moie complete approach of the diaphragmelectrode toward the back electrode. In effect, this action; as will be more particularly made apparent hereinafter, produces a complete Vibration of the diaphragm-electrode by reason of the movement o't' the flexible walls of the recel tacle, and as the front and back walls of the receptacle are of springy or resilient material they are adapted to serve as supplemental front and back vibratory diaphragms and as medium of yielding and resilient connection between the main diaphragm and the bridge. The two springy supplemental diapliragms constitute a resilient connection i'oi yieldingly and resilicntly opposing relative movement between the two electrodes which alternately compress and release the granular carbon. A transmitter constructed on this principle is exceedingly elicient and sensitive and is capable of a powerful and natural transmission of the voice tones, notwithstanding' the fact that it is simple and comparatively inexpensive to manutactru'e.

My invention has certain other objects in View relating more particularly to adjustment and compactness, which will be particularly set forth by reference to the accompanying drawings, in which Figure l is a `vertical section of the complete apparatus shown assembled together. Fig. 2 is a rear view of the said apparatus with the outer casing removed. Fig. 3 is a view of the various parts non-assembled'but in their relative position to be assembled. Fig. 4 'is an enlarged vertical section through the receptacle containing the electrodes and the mass of granular carbons.

The transmitter is contained within an ordinary case A, which is cup-shaped in form, and the cover B, holding the mouthpiece D, 'is secured upon the cup-shaped casing in any suitable manner. The diaphragm E is. held against the cover B atits rim, so that the central portion thereof is at the inner end of the mouthpiece. The bridge H is bent upon the cover B, as shown at l1.. The parts thus described are ordinarily used in a transmitter.

The novel feature of my invention resides in the receptacleni'or holding the electrodes and the mass of granular carbon, which I have designated as a whole at J. This receptacle J; which is illustrated more clearly in the large View, Fig. 4, is comprised of two counterpart. portions, Fig. 3, which when joined together provide a circular-shaped shell or receptacle having two vertical walls j and and an intermediate annular ring Zbetween the vertical walls. These two walls j and t' are of'thin metal and are consequently iiexible. The annular ring Z, presenting a cross-section of the material, joins the two flexible walls together and, as will be seen, imparts the movement of one wall to the other. The flexible wall /c is electrically connected to the diaphragm E by the contacting sleeve m, and the metal disk n, is also electrically connected to the diaphragm by meanaof the screw-threaded stem o and nut'secured upon Saidstem.

The diaphragm-electrode K, consisting of a carbon disk, is secured upon the metal disk a in any suitable manner. A sleeve p is rigidly held in the bridge H by means to be described, and the stemv q extends within said sleeve p, these parts being isolated by the insulating-sleeve fr. A disk .s is secured upon the inner end of the stem q, and the back electrodeoi' carbon L, consisting of a disk of copper, is mounted upon the metal disk s. A mass of granular carbon M is disposed within the receptacle J between the diaphragmelectrode K and the back electrode L. rlhe stem q and disk s, carrying the b ack electrode L, are securely held in position by means of the nut t upon the outer end oi' the stem q, said nut t being insulated from the sleeve p.

I provide a gripping-yoke of counterpart members N and O, Fig. 2, which are bolted together and encircling the sleeve g1 to hold the same secu rely and rigidly in position upon the yoke.

The stem r1, bearing the disk s, which carries the back electrode L, is connected by a wire P with aconducting-stem Q, which latter is connected with one of the circuit-leads. The other one of the circuit-leads may be cpnnected at any suitable point to the casing A.

The operation oi my device is as follows: When the diaphragm E is vibrated by the impact of the sound-waves, its movement of vibration is transmitted to the flexible wall at the point of connection between the said wall and the sleeve nt and stem o. Assume the movement of the diaphragm to'be inward, the disk 'nl is'a`lso moved inward within the receptacle'J by its connection to the stem o, thus causing the diapln'agm-electrode K to have an inward movement to compress the mass of granular carbon M between its surface and the surface of the back electrode L, which is held in a stationary position by the disk s and` the stem 1] held rigidly in the yoke H. As stated, the flexible wall yields and upon its inner thrust dishes at its center, and this movement of the liexible wall is communicated to the opposite flexible wall j by means of the intermediate annular ring Z, the wall j thus dishing its outer edge as it is held at the center rigidly by means of the sleeve 2). This yielding of the two walls 1 and j permits the d iaphragm-electrode K to obtain a wide range of movement in order to compress or release the mass of granular' carbon, and when the diaphragm by its opposite oroutward movement releases'the inward pressure upon said walls they return to their normal position, the wall j being stopped and held from false vibration by means of the engagement with the disk s and fiexiole wall j.

In use the forward thrust of the diaphragm E will tend to dish the forward wall 7c, and this forward thrust will then be communicated through the insulating-ringl and the peripheral portions of the casing to the back wall j. In this way the forward thrust of the diaphragm E operates to momentarily Hex the walls /c and j in such manner as to cause them to become concave on their outer surfaces. By thus yielding to the inward or forward thrust ofthe diaphragm E the back wall j permits the carbon disk or electrode K to approach much closer to the carbon disk or electrode L. ln this way the vibratory movement orshift on the part of the electrode K is increased to quite an extent, and by so ldoing an increased agitation of the granular roo carbon is of course also secured. As stated, the exing or yielding of the back wall j results in a momentary dishing of this wall and also the forward wall 7c, each wall being momentarily rendered concave on its outer Surface. lt will be observed, however, that an outward or reverse movement on the part of the diaphragm E will not cause the walls .7c and 7' to flex in an opposite direction-that is to say, in suc manner as to become-convex ontheir outer surfaces. This is due` to the fact that these walls and j are held against bulging or becoming outwardly convex by having their' inner surfaces arrangedto bear against the hat outer surfaces of the plates a ands. This will be readily understood by referring to Fig. il, in which it will be seen that thecentral portion of plate k is clamped Y tightly between the sleeve m and the. plate n and that in a similar way the central portion of plate j is clamped tightly between plate s and the sleeve p. In this way the walls 7c and n j are made .capable of 'flexing or dishing in such manner as to render theirv outer surfaces concave, but never in such Amanner as to cause then' outer surfaces to bulge or become convex.'v In this way the granular carbon and the carbon electrodes are inclosed in a flexible casing, which is preferably sealed by the ring ZV'. -The yielding character of the back wall ofthe carbon casing thus provided insures a greater and more natural vibration on the part of the diaphragm E and carbon y electrode K, thereby insuring the desired in- .crease of agitation on the part of the granular carbon.

While the peripheral portions of the sheetmeta-l casing are, as stated, non-flexible and unyielding, the front and back walls are of a springy or resilient nature, and therefore yield A to the forward Athrust ofthe diaphragm. Be-

ing composed of springy or resilient sheetmetal walls, the casing which thus incloses the carbon electrodes and 'granularcarbon is capable of restoring itself to a normal conditionthat is to say, of-res'torilng the two elecl trodes to their normal relative positions when the diaphragm ceases to vibrate. In other words, these two resilient or springy front and back walls of the carbon box or casing serve as supplemental diaphragme, which vibrate with the main oracoustic diaphragm E.

`The metal sleeve held by the bridge H serves as a backing for opposing the forward thrust of the diaphragm,.and' it is between the back electrode and the end of this backing that the middle portion of the back iexi-ble or "'springy wall of the sheet-metal casing is clamped or held. In this Way .the central portion of the iiexible back wall j is held against movement, and with the relative proportions of the back electrode and the sleeve pt-he outer or perlpher'alp'ortions of this back wall are prevented from moving forward oftheir normal position; ,In other wordsfthe marginal or outer portions of this `bach-'wall j' are arranged to'yield to the pressure of the diaphragm and move back to some extent, but are prevented by the back electrode from moving in an opposite direction. Thus the back flexible-or sprin'gy wall of the carbon-box is permitted `to dish or become outwardly concave, 4but never becomes outwardly convex. The front wall le is, however, so mounted andv held as to be capable of becoming either concave or con- Vex onits outer surface. fact that the front electrode is provided with a reduced hub portion 7s', against which the said front wall is clamped by the sleeve m. This construction provides a slight'space between the plate n of the front electrode andthe inner surface of the said flexible front wall. In

This is dueto the this way/when -the diaphragm moves forward this front wall becomes dished or concave 'on its outer surface, andwhen the diaphragm re'- acts or draws back the 'said wall may then become more-or less convex ,on its outer surface. Furthermore, it will be seen'that with this arrangement the front flexible wall has.

both a` bodily and a flexing or vibrating movement. VVhle the middle vportion of the back wall is held against movement, thev middle portion of the front wall is permitted to move with the diaphragm,- and owing to the lexibilityof the back wall the said front wall" also has a slight bodily movement in addition to its flexing or bending. While the ring Z and the plate or disk j serve to insulate the backelectrode from the sheet-metal casing, the arrangement is such vthat the front electrode and said casing are electrically con nected. With this arrangement the electrical circuitincludes the terminal orcontact Q, the wire P, the stem q of the back electrode, the disk or plate S, and the carbonv plate L of the back electro'de,.the granular carbon M, the carbon disk K, the metal plate oz of the front electrode, the hub portionk of the front electrode, the flexible or sheet-metal casing which incloses the electrodes and'carbon, the metal sleeve p, the bridge H, the casing A, and the boss a on the said casing, the latter serving as the other contact or terminal. In this way it will be seen that the current does not traverse the diaphragm and that the arrangetain objectionable connecting devices hereto- Y fore employed in transmitters of .this charac- As stated, the current ows'through ter. the transmitter-casing and thev electrodesfandback to the terminal or contact @,the resilient or springy sheet-metal casing which incloses the carbon servingr asmedium ofelecf trical connection betweenthe front electrode and the bridge H. As explained, the sheet metal casing or box Vfor inclosing the carbons is preferably made in two sections` each of which ispreferably provided Awith a flange.

-The two flanges can be united by the clamp- `ing-rmirl, and the character f f the closure IIO 11.5 ment obviates the necessity of employing cer-` in the/order'mentioned, the said box or're-- not the box, between the back electrode andy can be such as to hermetically seal the easing and4 inclose the carbon. Solder of course can be employed, if desired, tov eifect the closure and to permanently seal and connect the two sections of the easing.

As illustrated, it will be seen that the metallic sleeve ,f the metal box or receptacle J, the vibratory or front electrode, the granular carbon, the stationary back electrode, and the metal ste1`n1g are all connected up in series ceptacle constituting mediumof electrica-i connection for the, ow of current between the said sleeve and stem. This 'arrangement obviates the necessity of including the main diaphragm in the electrical circuit.

the peripheral portions of the box, a slight bodily vibration on the part of the box, and consequently a relative movement ofthe nperipheral portions of the box first towardpand then awayfrom the main diaphragm. Thus constructed the transmitter is of an exceedingly satisfactory and eiiicient character and well calculated to insure improved transmission.

It will be seen that one of the novel features of my .invention consistsof two thin ret silient walls, each provided with an electrode and rigidly supported at their outer edges, together with granular carbon'or other equivaient material interposed between the two electrodes, and as to the three elements-to wit, one electrode, another electrode, and means for rigidly supporting the said walls at their outer edges-at least one of said three elements being held stationary, whereby the granular carbon isv subjected to variable'pres- -sure when the two walls are iexed or vibrated,

together with main diaphragm means adapted to receive the voice-v i'brations and connected to 'alternately compress the' centers ofsaid auxiliary diaphragms toward each other and draw the same apart and to thereby produce the relative movement between the two op posed electrodes.

What I claim as my invention is as follows: l. 1n a telephone-transmitter. the combination with the diaphragm and mountings thereof, of a carbon-holdingl receptacleeompris'ing iexible springing walls and. an intermediate inflexible rim, a vcarbon disk comprising one of the electrodes within said receptacle rigidly connected with the diaphragm, one of the said walls being also connected with said diaphragm, and yielding under the iniiuence thereof, another disk of carbon within said receptacle constituting the back electrode, also connected with the other flexible wall which likewise yields under the influence of the dia phragm, said back electrode being stationary,d and granular carbon intermediate between saidelectrodes, whereby the said walls move with the movement of the diaphragm.

2. A telephone-transmitter comprising a diaphragm, front and back electrodes, the fron t-eleetrode being connected by a stem with thesaid'diaphragm, granular carbon between said electrodes, a sheet-metal box Aor casing inclosin'g said electrodes and granular carbon, said box or casing being provided with springy or resilient front and back walls which yield and permit the front electrode .to approach the back electrode, and a backing for holding the backelectrode and the middle portion of the said springy or resilient back wall against movement.

3. rA telephone-transmitter comprising a diaphragm, a front electrode connected to vibrate with said diaphragm, a back electrode held ,by a stationary backing, granular carbon between said electrodes, the said front electrode being provided on its back with a hub or raised portion, a box or casing inelosing said electrodes and granular carbon, said box or casing being provided with relatively thin springy or resilient front and back walls, a

nut and sleeve for. clamping the said front wall against the said hub or raised portion on the front electrode, the said front wall thereby being permitted to flex or bend in either direction, a nut and sleeve for clamping the middle portion ot' the said back wall against the iat back or outer surface of the said' back electrode, the said back wall thereby being .permitted to iiex or bend in one direction only,

and the two resilient or springy walls thus held being adapted to yield to the thrust of the diaphragm and permit the front electrode to approach the back electrode.

4. A telephonetransmitter comprising a diaphragm, a backing, a springy or resilient sheet-metal orcasing'serving as a yield` ing connection between` said diaphragm and said backing, front and back electrodes and granular carbon inclosed by said box or casing, suitable insulation for insulating the said box or casing from the said back electrode, said front electrode being electrically connected with said box or casing, a suitable transmitter casing or body structure, elecl trical connection between said easing or body structure and said springy or resilient box or casing, the saidtransmitter casing or body' structure therebyserving as one terminal of the electricalcircuit, and a termi nal or contact piece electrically connected with the back.

electrode and insulated from said transmitter casing or body structure.

5. A\telephonetransmitter comprising a Isuitable body structure, aldi'aphragm, a relatively large front electrode connected to vibrate'with said diaphragm, a relatively small back electrode, the said front electrode having its middle portion provided with a hub or springy or resilient front and back walls, a nut and sleeve 1for clamping the front wall against the said hub or raised portion on the front electrode, granular carbon between the two electrodes and inclosed by said box or casing, a sleeve of less diameter than the back electrode having'its end portion adapted to clamp the middle portion of the said back Wall againstthe back electrode. insulation between said sleeveand said back electrode, a bridge having a middle portion adapted to clamp upon the said sleeve, so as to hold the back electrode against movement, an insulatedx ter- ,minal with which the said back electrode is 25, electrically'connected, and the said body structure serving as the other terminal and being electrically connected through the medium of. the said sheet-metal box or casing with the front electrode.. c,

6. A telephone-transmitter comprising a suitable body structure, adiaphragm and front electrode connected to vibrate together, a back electrode of less diameter than the front electrode, a stem extending from the back of said back electrode` a stem and a, hub or raised portion projecting from the outer surface of the front electrode, a sheet-metal box or casing inclosing said electrodes, granular carbon between said electrodes, a nut and a sleeve applied to the stem on the front electrode, so as to clamp the front wall of said box or casing against said hub or raised portion on the front electrode, a'metal sleeve insulated from the stem on the back electrode, a nut applied to the stem on the back electrode and adapted to clamp said insulated sleeve and the middle i portion of the back' wall of said box or casing' against the said back electrode, an insulatingring for insulating the granular carbon from the said box or casing, a layer of insulation between the back electrode and said boxor casing, a bridge or clamping piece adapted to clamp upon the sleeve or the stem of the back raised portion, a sheet-metal casing having posed of two sheet-metal cups -having joined marginal portions and adapted to inclose saidelectrodes, granular cai bon between said elec'- trodes, and a'backing for holding one of said electrodes and a portion of said springy or re. 70 silient sheet-metal casing against movement.

8. In a telephone-transmitter,the combination of a diaphragm, a front electrode having suitable connection with 'said diaphragm, a stationary back electrode, granular carbon between said electrodes, and a springy or resilient sheet-metal casing inclosing said carbon. and electrodes, said casing being composed of' two cup-shaped parts having joined perimeters. g 8O 9. In a telephone-transmitter, the combination of a suitable diaphragm, a front electrode connected to vibratefwith said diaphragm, a

stationary back electrode, granular carbon be. tween said electrodes, a springy or resilient 35 sheet-metal casing composed of two sections and arranged to inclose said carbon and electrodes, each section of the sheet-metal casing being provided with a ange, and a clampingringA applied to.said vflanges and adapted to join the two sections of said box or casing.

10. In a telephone-transmitter, the combination of a diaphragm, front and back electrodes, granular carbon between said elec-, trodes, mechanical connection between the front electrode and the diaphragm, a stationary'backing for said back electrode, a springy or resilient sheet-metal casing serving as electrical connection between said front electrode of two cup-shaped parts having their perimeters joined and inclosing said granular carbon and said electrodes. i

11. In a telephone-transmitter, the combination of a suitable diaphragm, relatively movable electrodes, granular carbon interposed betvveen said electrodes, suitable connec- Vtion whereby the vibration of the diaphragm causes relative vmovement between said electrodes, a springy wall between said electrodes IIO and said diaphragm, a springy wall on theA other side of said electrodes, a nom-yieldingr connection between lsaid walls, anda mem benfor preventing movement on the part of the springy character of the two walls permitting the vibrations of the diaphragm to cause the desired relative movement between the two electrodes.-

12. In a telephone-transmitter, the combi- 12d nation .of a main diaphragm, front and back supplemental springy diaphragms suitably connected with said main diaphragm, front and back electrode-surfaces, granular carbon interposed between and resting in contact with said electrode-su rfac'es, and astationary backing connected with the central portion of the said back supplemental diaphragm andadapted to prevent-vibrations of the central portion of the said back supplementalA diaphragm, the 13 0 and said backing, said casing being composed I the middle portion of said last-mentioned wall, I I5 front and back electrode-surfaces being vibratory relatively to each other.

13. In a telephone-transmitter, the combil nation with a suitable diaphragm, of a'chaml ber yieldingly mounted th: reoii, an electrode i in said chamber and moving therewith, the electrode haviiig a greater extent of iiiovement than the chamber, an independently and l adjustably supported stationary electrode opi posed to.said first-mentioned electrode and having a piston-like movement relative to said chamber, and comminuted material between said electrodes, the said chamber having a springy wall constituting a part and secured to the balance thereof to which springy wall the independently-supported electrode is secured.

14. In a telephone-transmitter, the combination with a suitable diaphragm, of a chamber yieldingly mounted thereon. an electrode in said chamber and moving therewith, the electrode having a greater extent of movement than the chamber, an independently and i adjustably supported stationary electrode opposed to said first-mentioned electrode and having a piston-like movement relative to said chamber, and comminuted material between said electrodes, the said chamber having a springy wall constituting a part and secured to the balance thereotI to which springy wall the independently-supported electrode is secured.

15.` In a telephone-transmitter, the combination lwith a suitable diaphragm, ofv a chamber yieldingly mounted thereon, an electrode in said chamber and moving therewith, the electrode having a greater extent of movement than the chamber, a rigidly-secured electrode opposed to said lirst-mentioned electrode, and having a piston-like movement i'elative to said chamber, and comminuted material between said electrodes, the said chamber having a springy wall constituting a part and secured to the balance thereof to which springy Wall the rigidly-supported electrode is secured, and means whereby relative adjustment between the said electrodes may be effected.

16. In a telephone-transmitter, the combination with a suitable diaphragm, of a chamber yieldingly mounted thereon, an electrode in said chamber and moving therewith, the electrode having a greater extent of movement than the chamber, an independently-supported stationary electrode opposed to saidy first-mentioned electrode and having a pistonlike movement relative to said chamber, and comminuted material between said electrodes, the said'chamber having a springy wall constituting al part and secured to the balance thereof to which springy wall the independently supported electrode is secured, and means whereby relative adjustment between the said electrodes may be effected.

17. In a telephone-transmitter, the combination of a diaphragm, front and back elecl trodes, a metallic box inclosing the said electrodes, comminuted material interposed between vsaid electrodes, insulation between said comminuted material and the inner surface ot said box, the front electrode being electrically connected with the box and the back electrode being-insulated therefrom, a metallic stem secured to the back electrode, a sleeve of insulation on said stem,a metallic sleeve on said sleeve of insulation, the said metallic sleeve being electrically connected with said box, and a metallic member in which said metallic sleeve is adjustably clamped.

18. In a telephone-transmitter, the combination of a diapl'iragm, front and back elecmentioned terminal and the front electrodev incl udingsaid bridge and box, the comminuted material and back electrode being insulated from the box and bridge.

19. In a telephone-transmitter, the combination of a diaphragm, jfront andback electrodes, the front elec-trode being connected with said diaphragm, a bridge for adjustably supporting the stationary back electrode, commin uted material interposed between said electrodes, and a box inclosing said electrodes and comminuted material, said box having flexible and springy front and back walls serving as medium of yielding connection between the said diaphragm and bridge.

20. In a teleplione-transiiiittei', the combination of a main diaphragm, a movable electrode carried by said diaphragm, a suitable support, a stationaryelectrode mounted upon said support, comminuted material between the opposing surfaces of said electrodes, and a box inclosing said electrodes and comminuted material, said boxhaving lat front and back walls of thin, flexible and springy material adapted to serve as medium of resilienteonneetion between said diaphragm and support.

21. In a telephonr transmitter, 'the combination of a m'ain diaphragmfa front electrodesurface adapted to vibrate with the diaphragm,

a suitableI support, a back electrode-surface adaptedto remain stationary with said support, conimin uted material interposed between said electrode-surfaces, and means for inclosing saidk comminuted material including front and back supplemental diaphragms, said supplemental diaphragins consisting of thin flat pieces of springy material adapted to serve as medium of resilient connection betweentlieA ioo Idro

its

Igo

trode connected with said diaphragm, a stationary electrodeopposed to said vibratory electrode, comminuted material interposed between said electrodes, anda box inclosing said electrodes and comminuted' material, said box 28. In a telephone-transmitter, the comhi nation of a main diaphragm, front and back supplemental diaphragms of yielding and springy material, front and back electrodes'urfaces carried by said front and back supplemental diaphragms respectively, comminuted material interposed between said elec- Y trode-surfaces, suitable connection between SiO the main diaphragmand the front electrodesurface and su pplemental diaph ragm,^a bridge, and' adjustable connection between the said bridge and the said back electrode-surface and supplemental diaphragm, the center of said back supplemental diaphragm being held stati0nary by said adjustable connection, whereby said bridge and supplemental diaphragme yieldingly oppose the vibrations of the main diaphragm in both directions.

24. In a telephone-transmitter, the combination of a metallic sleeve, a metallic boxlor inclosure, a vibratory front-electrode, a mass of granular carbon, a stationary back electrode, and a metallic stem, all connected up in series in the order mentioned,l the said sleeve inclosing the said. stem, a diaphragm connected to vibrate said front electrode, and a bridge supporting the said sleeve and stem and holding the back electrode against movement.

25. In a telephone-transmitter, the combination of a metallic sleeve, a metal box with a flexible back wall, a vibratory front electrode, a mass of granular material, a stationary back electrode, and a metallic stem, all connected up in series in the order mentioned, the said sleeve inclosing the said stem, a diaphragm connected to vibrate said front electrode, such vibrations being' yieldingly opposed by said ilexible wall, and a bridge supporting the sleeve and stem and holding the back electrode against movement.

26. In a telephone-transmitter, the combination of a metallic sleeve, a metallic box composed of front and back walls having their perimeters or peripheral portions tightly fastened together, a vibratory front electrode, a

4mass of granular material, a stationary back electrode, anda metallic stem, all connected up in series in the order mentioned, the said sleeve in closing the said stemf'a diaphragm connected to vibrate said front electrode, and

A a bridge adjustably supporting said sleeve and thereby normally holding said back electrode against movement.

27.- In a telephone-transmitter, the combination of a vibratory front electrode, asta-- tionary back electrode, granular carbon interposed between said electrodes, a diaphragm i for vibrating the said front electrode, and a bodily-vibratory box inclosing said electrodes and granular carbon. said` box having thin fiat resilient front and back walls, whereby the bodily vibrations of said box are of less amplitude than the vibrations of said front electrode.

28. In a telephonetransmitter, the combination of a metallic sleeve,v a'metallic auxiliary diaphragm, a vibratory iront electrode,

a mass of granular carbon, a stationary back electrode, and a metallic stem, all connected up in series in the order mentioned, the saidsleeve inclosing the said stem, a diaphragm for vibrating the front electrode, and a metallic member adjustably supporting the said sleeve and thereby normally holding said back electrode against movement.

-29. A telephonetransmitter, comprising -front and back electrode-surfaces, granular carbon interposed in suitable quantity directly between said surfaces, a main diaphragm connected with the front electrode-surface, a snit` able vibration-opposing member connected with the rear electrode-surface, the granular and perfectly-Hat resilient front and back walls connected respectively with said diaphragm and member, and said box having also an annular non-yielding wall or peripheral portion connecting said resilient front and back walls, whereby said i'lat front and back walls consti'- tute medium of resilient connection between said diaphragm and member; and whereby said carbon is subjected to variable pressure by said electrode-surfaces together with a casing rigidly connected with said member, whereby the center of said resilient back wall is held stationary.

30. A telephone-transmitter comprising a back electrode, a stem on said electrode, a metal plate through which the stem extends, insulation between the said plate and electrode, a

'sleeve mounted on and insulated from the said carbon being inclosed by a box having thin v IOO vIIO

end of said stem, andl insulation encircling the stein and interposed between the said nuts and the end'of ythe sleeve, whereby the cup.l

insulation and sleeve are clamped tightly between the electrode and one of said nuts.

32.,A telephone-transmitter comprising a disk having its face acting as an electrode and its back provided with a threaded stern, a metal cup inclosing the electrode and through which the said stern extends, 'a nut on the end of said stem, a sleeve mounted on the stem and insulated therefrom, said vsleeve being clamped endwisc -between the cup and nut, and suitable insulation between the electrode and cup.

33. A telephone-transmitter comprising two thin and perfectly smoothl resilient auxiliary d iaphragms carrying front and back electrodesurfaces with granular carbon interposed in suitable quantity directly between said surfaces, means for holding the center of one of said diaphragms stationary, together with main diaphragm means adapted to receive the voice vibration and connected to alternately compress the centers of said auxiliary diaphragxns toward each other and draw the same apart, and to thereby produce the relative movement between the two opposed electrodes.

34. A telephone-transmitterA comprising a box composed of a rigid ring closed at each side by a thin resilient auxiliary diaphragm, eppositelyarranged electrodes secured to middle portions of said thin resilient auxiliary diaphragms, granular carbon interposedbetween said electrodes,a casing rigidly connected with one of said electrodes, together with main diaphragm means adapted to receive the voice vibration and connected to alternately compress the centers of said auxiliary diaphragms toward,\,ach other and draw the same apart, and to thereby produce the relative movementbetween the two opposed electrodes.

35. A telephone-transmitter comprising a casing, a pair of oppositely-arranged electrodes, granularl carbon between said electrodes, means for inclosing the electrodes and granular carbon consisting or' two thin resili ent auxiliary diaphragms rigidly separated at their margins, and as torthe three elements,

to wit, one electrode, another electrode, and the means for rigidly separating the two resilient auxiliary diaphragms, at least one of such elements being stationary and rigidly connected with the said casing, together with main diaphragm means adapted to receive the voice vibration and connected to alternately compress the centers of said auxiliary dia phragms toward each other and dra\ 'the same apart, and to thereby produce the relative movement between the two opposed electrodes.

86. A teleplione-transmitter comprising a casing, a pair of oppositely-arranged electrodes, granular carbon between said electrodes, means for in'closing the electrodes and granular carbon consisting of two thin resilient auxiliary diaphragrns rigidly separated at their margins, and as to the three elements,-

to wit, one electrode.` another electrode,'and

the means for rigidly separating the two re HENRY l. CLAUSEN.

Witnesses:

Guns. (l. BULKLEY, H Anni' l. BAUMGAu'rNnn. 

